I'm having trouble keeping my dolphin striker, on the 17, tight with out severly canting the hulls in. I tried loosening the mast post and bringing the bottom nut up to give it a little more length, but not able to get it to move even with the dolphin striker very loose. Have even tried driving the post down with a soft dead blow mallet, but it will not budge. Any suggestions?

Have already done that, the boat is completely apart and I have removed the dolphin striker from the crossbar. Was able to get both the upper and lower nut loose on the mast post will turn freely, but it will not go down any. I know there is a sleve in the crossbar, but is there something else that would prevent the post from moving down a little? I have about given up on moving the post and will try adding ss washers behind the nuts on the outer ends of the rod. I hope that will allow me to keep the boat tight without canting the hulls in.

Sounds like the post is fused to the sleeve inside the crossbar. Perhaps some liquid loosening material can be poured in there? The sleeve and post should pull out the bottom of the crossbar I think. Usually the brossbar is drilled larger on the bottom to allow the dimension of the sleeve to fit in.

I have removed the dolphin striker rod and have the post rotating freely, but it will not go up or down. Gave up on that idea and have added washers behind the nuts on the end of the dolphin striker rod. This has allowed me to tighten it up with less inter canting of the hulls. Looks like this will work, but still at a loss why the mast post would not move in either direction with everything loose and the ds rod removed.

It involves using the actual threads and nut on the post to "jack" the post out of the sleeve. (In my 86 H17 every nut or bolt I have had to remove has needed some thoughtful coaxing - so my mind is in this mode.)

Stack a few greased washers (as thrust washers) against the cross bar. Then jack the rod out with the nut. While trying to jack the post out, it will rotate. So, create a "bolt head" to grab onto with a 2nd wrench; using two nuts tightly counter-rotat to lock at the post-end. To jack - apply a wrench to one of these "bolt head" nuts to stop rotation, and another wrench to the jacking nut to actually jack the rod, drawing it out of the sleeve.

I am sure you will have to tweak this approach; stacking washers etc... to achieve proper spacing etc.. but this method sounds reasonable to me.